Oil and gas within tanks, or vessels, placed at or near oil and gas wells are commonly heated as part of a preliminary refinement process using heating systems and a combustion management system. The combustion management systems are generally used to heat and monitor a medium drawn through a heating vessel. The combustion or flame used in this process occurs in a combustion chamber near an airplate.
The ability to control combustion or flame ignition is a key feature of combustion management systems. Combustion management systems often rely on an electrical spark to initiate combustion or flame at the combustion chamber. A common method of creating a spark is to use a transformer coil to convert a low voltage power source into a high voltage current capable of arcing between two conductive points; the arcing creating a spark that is used to initiate combustion or a flame.
The transformer coil is typically maintained outside of the combustion chamber and may have wires extending from the transformer coil to an electrode that may be disposed near the situs where the combustion or flame is initiated. Ignition may be controlled using a control box that communicates when a spark should be created at the electrode, to initiate combustion, by controlling power to the transformer coil.
A common feature of a coil system is a coil housing. The coil housing is often used to cover the transformer coil, which helps protect the transformer coil from weather or damage from unwanted contacts and may reduce the risk of personnel coming into contact with high voltage electrical currents.
However, coil housings currently used in combustion management systems have a number of disadvantages. One disadvantage with coil housings currently being used in combustion management systems at oil and gas well sites is the risk of unwanted arcing, particularly between terminals, because of the high voltage generated by the coils. Unwanted arcing is any arcing of current from point to point (e.g., between terminals) other than at the site where the arcing is intended to create the spark for initiating flame (e.g., at the end of the electrode in the combustion chamber). When unwanted arcing occurs, the coil may not transfer current properly. Further, unwanted arcing increases the risk of damage or injury to equipment and personnel.
The risk of unwanted arcing may increase when terminals have more exposure to air. The risk of unwanted arcing may also increase as the distance between the terminals decreases. Coil systems currently being used in connection with combustion management systems may have several terminals which extend outside the coil housing, thus being significantly exposed to air.
Another disadvantage of many coil housings currently being used in connection with combustion management systems is that they may be restricted to larger sizes because of the need to keep the terminals separated by sufficient distance to prevent arcing.
Another disadvantage of many coil housings currently being used in connection with combustion management systems is that the coil systems often must be mounted in a location that is inconvenient for maintenance and repair, as a more accessible location poses a risk of incidental, unwanted arcing with a nearby tool or object. Thus, current transformer coil systems are typically placed in more inconvenient locations to mitigate the risk of unwanted arcing, because the coil housings may not provide adequate protection to the terminals or against other unwanted arcing. However, such locations that protect against contact with external elements are also locations that may be inconvenient or inhibit access to the coil system for maintenance and repair. Additionally, the efficiency of the coil system decreases as the distance between the coil system and the point of spark at the combustion chamber increases.
Another disadvantage of many coil housings currently being used in connection with combustion management systems is that the coil housing may not allow for more than three terminals, thus limiting the function of the coil systems. The location and number of terminals may be limited because certain terminal arrangements increase the risk of unwanted arcing.
Because coil terminals in existing coil systems extend from the coil housings and are exposed to the air, configuring coil systems with the coil terminals disposed closer together or with more than three coils may be challenging and create safety concerns and increased risk of unwanted arcing.
Another disadvantage of coil housings currently being used in connection with combustion management systems is the risk of unwanted arcing during the repair and maintenance of the coil system. When a tool comprising conductive material, such as a metal screwdriver, is brought in close proximity to the coil or coil terminals, the coil is more likely to arc and shock the individual holding the tool because the coil housing does not completely insulate the coil terminals.
It is thus desirable to have a coil system and housing that mitigates the risk of unwanted arcing when a coil is repaired or maintained; that restricts contact with external elements without requiring remote or inconvenient placement of the coil system; and that allows for more freedom in both the number and placement of coil terminals.